Anthracene derivatives and process of making same.



UNITED STATES PATENT OFFICE- ARTHUR ZITSCHER AND ERNST JULIUS BATH,OFFENBACI-I-ON-THE-MAIN, GER- MANY, ASSIGNORS TO CORPORATION OFCHEMISOHE EABRIK GRIESHEIM ELEK- TRON, OF FRANKFORT-ON-THE-MAIN,GERMANY.

AN'IHRACENE DERIVATIVES AND PROCESS OF MAKING SAME.

No Drawin 'g.

To all whom it may concern Be itknown that We, ARTHUR ZITSCHER andERNsrJULIus BATH, doctorsjof philosophy, chemists, andsubjects of theGerman Emperor, and .residents of Offenbach-on- -.the-Main, Grand Duchyof Hesse, Germany,

with the post-office address F riedrichstrasse ,31 and Kaiserstrass'e115", respectively, haveinvented new"and i useful Improvements in.Anthracene Derivatives and Processes of Making Same, "of which thefol-lowing is a specification.-

Homer has Deutschea QZ zemz'schen Gesellschaft vol;- 15' page 224 aprocess for the manufacture of Q-aminoanthracene (calhed by Liebermannwhich-scan easily be re-converted into the original compound, that is tosay into 2- aminoanthraquinone; this bddy therefore cannot bebeta-anthra'min. It thus appears that Rome'r was unable to makebeta-anthration in presence of alkali.

We have found that Q-aminoanthraquinone, those of its derivatives whichdonot contain sulfo groups, and the products of reduction-of thesebodies which are soluble I in alka1i,-s1ich as beta-aminoanthranol canbe advantageously transformed into betaanthramin by treatment with zincin'pre's-v ence of an alkali, the action being continued untilsubstantially none of the product of 40 i reduction soluble in alkaliremains. The invention is'b'ased on the said discovery and isillustrated by the following examples, theparts being by Weight.

' Example I: parts of Q-aminQanthra- 'quinone' are heated in a refluxapparatus with 500' arts of 'ammoniasolution'of specific gravity 0.91and l00-parts of zincdust,

for 10 hours. There is formed a brown-red solution from which thebeta-anthrami'n is precipitated as canary-yellow crystals, which.

Specification of Letters Patent. :Application filed February 24, 1912.Serial No. 679,686.

. f Example described inlthe Bem'ohte 'der' min from.2-aminoanthraquinone by reduc-.

- Patented J uile 4, 1912.

are filtered and recrystallized from a solvent such as alcohol.

Example II: 50 parts of beta-aminoanthranolare heated in .a refluxapparatus with 350 parts of caustic soda lye of 35 Baum'specificgravity,1000 parts of water and 50 parts of zinc dust until noanthraquinone'd'erivative soluble in alkali remains, for instance for8.. hours.

irr ExampleI.

v III 100 parts of QG-dia'minoanlthraquinone. are-heated in areflux'apparar .tu's, 'With.,700 parts of caustic soda lye of 35 Baumspecific gravity, 1500 parts of .water and 200 parts of zinc dust for15- hours. The2:6-diaminoanthracene thus ob- :tained can be separatedfrom zinc dust by dissolution in alcohol. After recrystallization fromzylene'the product-melts at about- 250o "I V p "In aiialogous mannerother derivatives of 2-aminoanthraquinone, for examplehalogen-substitution products, are transformed into aminoanthracene orits derivatives, the

halogen atoms being completely or partly.

eliminated. Thus,"beta-anthramin can be obtained from 13+dibromo-2-amino-anthraguinone. Betaanthramin and its" deriva tives areapplicable in the manufacture of dye-stuffs.

Now What we claim and desire to secure by Letters Patent is thefollowing:

aminoanthracene derivatives consisting in treating "'anthraquinonederivatives, which do not contain sulfo groups and at leastcontainoneamino group in the beta position,

v The product is' isolated in manner'similar to that described Theprocess for the manufacture of 2- with zinc in. presence of an alkaliuntil the I product becomes insoluble in alkali substantially asdescribed. I In testimony, that We claim the foregoing as our invention,we have signed our names in presence of two Witnesses, this'ninth day ofFebruary 1912. V

ARTHUR ZIT'SCHER'. v ERNST JULIUS BATH.

Witnesses:

PETER LAUTENSOHLAGER,

FRITZ DESOR.

